Chemical weathering and Sr flux from the silicate lithology dominated fluvial system: Insights from major ions, dissolved Sr and 87Sr/86Sr of the teesta headwaters, Sikkim Himalaya

2021 ◽  
pp. 105171
Author(s):  
Satyabrata Das ◽  
Santosh K. Rai ◽  
Waliur Rahaman ◽  
Saurabh Singhal ◽  
Shushanta Sarangi
Keyword(s):  
Chemical Weathering ◽  
Major Ions ◽  
Fluvial System ◽  
Sikkim Himalaya

scholarly journals Hydrochemical Changes and Influencing Factors in the Dongkemadi Region, Tanggula Range, China

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1856
Author(s):  
Tianding Han ◽  
Yuping Li ◽  
Jia Qin ◽  
Xiangying Li ◽  
Qin Yang ◽  
...  
Keyword(s):  
River Water ◽  
Chemical Weathering ◽  
River Flow ◽  
Major Ions ◽  
Meteorological Data ◽  
Atmospheric Precipitation ◽  
Dilution Effect ◽  
Ion Concentration ◽  
Rock Interaction ◽  
Geochemical Model

In order to detect the source and controlling factors of hydrochemical ions in glacier meltwater-recharged rivers, the chemical characteristics of the river water, precipitation, and meltwater of the Dongkemadi River Basin, China, in 2014 (from May to October) were systematically analyzed, and combined with the hydrological and meteorological data. The results show that the hydrochemical pattern of the typical river was HCO3−-Ca2+. The most cations were Ca2+ and Mg2+, and the predominant anions were HCO3− and SO42−, in the river. The concentration of major ions and total dissolved solids (TDS) in the river water were much larger than that in the precipitation and meltwater. The TDS concentration was ordered: River water > precipitation > meltwater. The water-rock interaction and the dilution effect of the precipitation and meltwater on the runoff ions resulted in a negative correlation between the ion concentration of the river water and the river flow. The chemical ions of the river runoff mainly originated from rock weathering and the erosion (abrasion) caused by glacier movement. In addition, the contributions of different sources to the dissolved components of the Dongkemadi River were ordered: Carbonate (75.8%) > silicate (15.5%) > hydatogenic rock (5.7%) > atmospheric precipitation (3%), calculated by a forward geochemical model. And the hydrochemical weathering rates of carbonate and silicate minerals were 12.30 t·km−2·a−1 and 1.98 t·km−2·a−1, respectively. The CO2 fluxes, consumed by the chemical weathering of carbonate and silicate, were 3.28 × 105 mol·km−2·a−1 and 0.91 × 105 mol·km−2·a−1, respectively.

Atmospheric deposition versus rock weathering in the control of streamwater chemistry in a tropical rain-forest catchment in Malaysian Borneo

2014 ◽  
Vol 30 (5) ◽  
pp. 481-492 ◽  
Author(s):  
Naoyuki Yamashita ◽  
Hiroyuki Sase ◽  
Ryo Kobayashi ◽  
Kok-Peng Leong ◽  
Jamil Mohd Hanapi ◽  
...  
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Chemical Weathering ◽  
Major Ions ◽  
Water Discharge ◽  
Base Cations ◽  
Base Cation ◽  
Ion Fluxes ◽  
Small Catchment ◽  
Streamwater Chemistry

Abstract:Uncertainty about the H+ buffering capacity in tropical rain forest limits our ability to predict the future effect of anthropogenic deposition on the streamwater chemistry. Export of major ions to the stream and the ion-fluxes via rainfall, throughfall, litter-leachate and soil-water pathways were observed to examine the source of streamwater nutrients in a small catchment in Sabah, Malaysia. The streamwater and the ion-fluxes were measured for 3.75 and 2 y, respectively, by collecting water twice a month and setting ion-exchange-resin columns. Streamwater pH ranged from 6.5 to 7.6 and was not sensitive to water discharge controlling base cations. The NO3−-N, Ca2+ and Mg2+ fluxes were low in atmospheric depositions (0.6, 0.5 and 0.3 kg ha−1 y−1, respectively) and markedly increased in the litter layer. The NO3−-N flux decreased drastically from subsoil (70 kg ha−1 y−1) to the stream (1.4 kg ha−1 y−1) whereas the Ca2+ and Mg2+ fluxes were not different between subsoil (38 and 18 kg ha−1 y−1) and stream (30 and 15 kg ha−1 y−1). Neutral pH in tropical streams was mainly due to the base cation leaching with deep chemical weathering in deeper strata, and a rapid decrease in NO3− leaching from the subsoil to the stream.

Chemistry of Surface Sediments of Sixteen Lakes in the Experimental Lakes Area, Northwestern Ontario

1971 ◽  
Vol 28 (2) ◽  
pp. 277-294 ◽  
Author(s):  
G. J. Brunskill ◽  
D. Povoledo ◽  
B. W. Graham ◽  
M. P. Stainton
Keyword(s):  
Lake Sediments ◽  
Lake Sediment ◽  
Chemical Weathering ◽  
Major Ions ◽  
Fine Fraction ◽  
Dry Weight ◽  
Terrestrial Vegetation ◽  
Experimental Lakes Area ◽  
Sediment Samples ◽  
Northwestern Ontario

This paper contains some descriptive chemical data on bedrock, soils, and profundal lake sediments of the Experimental Lakes Area (ELA). The acid granodiorite bedrock and the plagioclase–K-feldspar–quartz glacial drift of the region exhibit low rates of chemical weathering. Terrestrial vegetation, soil organic matter, and the fine fraction of the glacial drift are concentrated in the lake sediments. The major minerals of the lake sediments are quartz, plagioclase, K-feldspar, illite, chlorite, kaolinite. Loss on ignition for the lake sediment samples varies from 18 to 62% dry weight, organic carbon from 8 to 34% dry weight, total nitrogen from 0.9 to 3.5% dry weight, and total phosphorus from 0.1 to 0.3% dry weight. These surficial lake sediment samples are 88–96% water, and concentrations of major ions in sediment interstitial water are 1.5–5 times the concentration of major ions in lake water.

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